Garmin 60CX showing wandering tracks I never made. Why?

[+Petermgr]

Hi everyone,

 

I picked up a Garmin 60CX yesterday and have been testing it out. Last night we went to find a geocache, no problems. However, I have noticed that the tracking wanders. I tested it this morning walking from my front door, around the block, and and back. When I imported the data into my Mapsource and into Google Earth I noticed a lot of tracks that I never made. Can't figure it out. The walk was consistent and the GPS had clear view of the sky.

 

 

WAAS enabled. MAP Datum, WGD 84. And btw, as I sit here at my desk, the tracking keeps moving on the GPS screen . . .

 

Any thoughts?

 

Thanks

 

Peter

[+PDOP's]

I think you're seeing "multipath' problems where the satellite signals are bouncing off obstructions (think ghosting on a TV using over the air signals) One drawback of the highly sensitive chipset used in the x series is that they'll pickup weak signals from satellites low on the horizon which are more prone to multipath problems.

[strumble]

Perfectly normal!

Everytime you switch on the unit it will create tracks similar to that even if you remain in your home.

If you wish to save a track you can easily remove those ghost movements from within MapSource before saving.

 

I would not show it to your neighbours as they may think you are a cat burgalar

[+imajeep]

By default, tracking is always on. You can go to the Tracks pages and turn it off, then turn it on only when you want to record a track.

[Hiker2008]

Were you drinking?

[+TrailGators]

I think you're seeing "multipath' problems where the satellite signals are bouncing off obstructions (think ghosting on a TV using over the air signals) One drawback of the highly sensitive chipset used in the x series is that they'll pickup weak signals from satellites low on the horizon which are more prone to multipath problems.

This happens to me when I'm hiking. It is annoying because it screws up my distance traveled. I didn't know that this is more of an issue for the SIRFstarIII chips....

[+PDOP's]

This happens to me when I'm hiking. It is annoying because it screws up my distance traveled. I didn't know that this is more of an issue for the SIRFstarIII chips....

 

Survey grade GPS receivers actually have a horizon mask setting which ignores satellites below a specified elevation (number of degrees) to minimize problems like this. If you're interested there's a long discussion about accuracy vs sensitivity on the sci.geo.satellite-nav newsgroup.

[+Petermgr]

Thanks everyone for the responses. Real eye opener. I have decided to return the 60cx.

 

"Hiker2008" . . . I was drinking last night after our geocache (Moslon Canadian, eh). But I was very sober this morning when the readings went nuts!

 

"strumble'. My neighbors are too busy watching for bears coming in the backyards . . .

 

"PDOP's" . . . nice site you have there! My son lives in Calgary so we will be visiting and will check out some of the caches you have posted . . .

 

"imajeep" . . . I did start fresh when I started my walk. The extra readings came during that walk. When I got back I received numerous other tracks while the GPS was sitting on my desk. I didn't include those in the screen shot . .

 

"TrailGators" . . . that is the main reason I am returning the 60cx. What's the point of a GPS unit if it doesn't give accurate information or questionable information? I know the 60cx has very high reviews and it is a nice unit. However, when paying top dollar I want something that won't cause me confusion

 

Thanks again . . .

 

Peter

 

View from cache last evening . . .

[+Miragee]

My trusty Garmin Vista C had a bad day a while back. I was standing in one spot, trying to get accurate coordinates for a cache I was placing that was close, as the crow flies, to two other caches. Needless to say, it was frustrating to be 80 feet away from the other cache, then .11, then 150 feet away, then .10.

 

 

I turned it off and back on, and it worked just fine after that. I think you will be very happy with your new choice.

[+TrailGators]

My trusty Garmin Vista C had a bad day a while back. I was standing in one spot, trying to get accurate coordinates for a cache I was placing that was close, as the crow flies, to two other caches. Needless to say, it was frustrating to be 80 feet away from the other cache, then .11, then 150 feet away, then .10.

 

 

I turned it off and back on, and it worked just fine after that. I think you will be very happy with your new choice.

You must have felt like a pinball...

[+TrailGators]

This happens to me when I'm hiking. It is annoying because it screws up my distance traveled. I didn't know that this is more of an issue for the SIRFstarIII chips....

 

Survey grade GPS receivers actually have a horizon mask setting which ignores satellites below a specified elevation (number of degrees) to minimize problems like this. If you're interested there's a long discussion about accuracy vs sensitivity on the sci.geo.satellite-nav newsgroup.

Thanks for the link!

[GreatCanadian]

A lot of people in this forum are saying that it is normal...i don't agree...may be normal for a 60cx but not for many other models....my 60cx does the same thing, but my legend c never did, and my current legend cx doesn't do it either....the tracking on those two is much more reliable than on my 60cx..when i use the gps on walk in fishing trips, i can follow the track out with the 2 legends, but with the 60cx, i cannot trust it's track...mine is for sale.

 

I realize that yes, consumer grade GPS's will have a certain degree of wandering, but that's not what i'm talking about. I'm talking about the reliability of the track put down by the gps. The track with my 60cx is NOT reliable. I don't trust it. I have full confidence in my legends. I've walked hundreds of miles with gps's, and i don't trust the track on the 60.

Edited June 3, 2007 by GreatCanadian

[robertlipe]

You can haggle about the definition of "normal". Let's go with "expected for that model". It was documented over a year ago. See "my ghost likes to travel" and "when in roam" at http://www.mtgc.org/robertlipe/showdown/

 

If you want the units best guess of its position at every moment - even if it drives you crazy with the sub-meter jitters - the garmin X series delivers. If you want highly averaged positions based on the units best guess of your current position staticaly averaged over time, there are better choices.

 

I can't say that I find the current behaviour of the X series very satisfying in this regard, but that's the way it is. You've already voted with your checkbook.

[+Searching_ut]

A lot of people in this forum are saying that it is normal...i don't agree...may be normal for a 60cx but not for many other models....my 60cx does the same thing, but my legend c never did, and my current legend cx doesn't do it either....the tracking on those two is much more reliable than on my 60cx..when i use the gps on walk in fishing trips, i can follow the track out with the 2 legends, but with the 60cx, i cannot trust it's track...mine is for sale.

 

I realize that yes, consumer grade GPS's will have a certain degree of wandering, but that's not what i'm talking about. I'm talking about the reliability of the track put down by the gps. The track with my 60cx is NOT reliable. I don't trust it. I have full confidence in my legends. I've walked hundreds of miles with gps's, and i don't trust the track on the 60.

 

It's normal for the etrex series as much if not more so than the sirf chip models. I've logged thousands of track miles hiking and mountain biking with GPS's and they all tend to have track offsets, wandering and other errors, often with the error being several hundreds of feet. It doesn't matter whether I use my Pocket PC based units, one of my several different etrex's, one of my sportraks, or any of my Forerunners. If you use the unit with road maps and lock to road turned on, it looks good, but thats because the track record is based on the computed position with the lock to road function. My magellans don't wander when stationary because of the auto averaging, but they still drift way off sometimes when recording tracks, all depending on the terrain.

 

If you're looking to record highly accurate trail data with any consumer level unit, you're going to have to cover the same trail several times, manually take care of obvious errors, then average out the trail data with software such as topofusion.

[MajBach]

Thanks everyone for the responses. Real eye opener. I have decided to return the 60cx.

 

"Hiker2008" . . . I was drinking last night after our geocache (Moslon Canadian, eh). But I was very sober this morning when the readings went nuts!

 

"strumble'. My neighbors are too busy watching for bears coming in the backyards . . .

 

"PDOP's" . . . nice site you have there! My son lives in Calgary so we will be visiting and will check out some of the caches you have posted . . .

 

"imajeep" . . . I did start fresh when I started my walk. The extra readings came during that walk. When I got back I received numerous other tracks while the GPS was sitting on my desk. I didn't include those in the screen shot . .

 

"TrailGators" . . . that is the main reason I am returning the 60cx. What's the point of a GPS unit if it doesn't give accurate information or questionable information? I know the 60cx has very high reviews and it is a nice unit. However, when paying top dollar I want something that won't cause me confusion

 

Thanks again . . .

 

Peter

 

 

I agree with you. My 76 CSX does the same thing and I don't like it. I would have accepted it as the nature of the beast if this was the first GPS I had ever owned but when the 7 year old Lowrance I replaced with it never did this, well, I'll think twice before I shell out all that cash for a Garmin in the future. Unfortunately, I invested too much $$$ in mapping before I realized the 60/76 series do this inherently and consistently.

 

BTW, nice pic. I have one from the same spot from the last time I was out there.

Edited June 3, 2007 by MajBach

[GreatCanadian]

A lot of people in this forum are saying that it is normal...i don't agree...may be normal for a 60cx but not for many other models....my 60cx does the same thing, but my legend c never did, and my current legend cx doesn't do it either....the tracking on those two is much more reliable than on my 60cx..when i use the gps on walk in fishing trips, i can follow the track out with the 2 legends, but with the 60cx, i cannot trust it's track...mine is for sale.

 

I realize that yes, consumer grade GPS's will have a certain degree of wandering, but that's not what i'm talking about. I'm talking about the reliability of the track put down by the gps. The track with my 60cx is NOT reliable. I don't trust it. I have full confidence in my legends. I've walked hundreds of miles with gps's, and i don't trust the track on the 60.

 

It's normal for the etrex series as much if not more so than the sirf chip models. I've logged thousands of track miles hiking and mountain biking with GPS's and they all tend to have track offsets, wandering and other errors, often with the error being several hundreds of feet. It doesn't matter whether I use my Pocket PC based units, one of my several different etrex's, one of my sportraks, or any of my Forerunners. If you use the unit with road maps and lock to road turned on, it looks good, but thats because the track record is based on the computed position with the lock to road function. My magellans don't wander when stationary because of the auto averaging, but they still drift way off sometimes when recording tracks, all depending on the terrain.

 

If you're looking to record highly accurate trail data with any consumer level unit, you're going to have to cover the same trail several times, manually take care of obvious errors, then average out the trail data with software such as topofusion.

 

No, as I said before, that is NOT the case with my other GPS's in comparison to the 60cx. As a matter of fact, just last evening (after my previous post) a friend and I rode 9 km on our atv's to go fishing. On the way out, his track was dead on, mine was 50 to 100 meters off MOST OF THE WAY OUT!! So to say that it is as much or more so in the etrex series is very innacurate. My friend's gps is a Legend C.

[+Petermgr]

Picked up a Legend CX. Took the same walk this morning. No wandering . . .

 

 

Also, my son has an old Legend, no wandering. Friend of mine has the Rhino, no wandering.

 

Thanks for all the feedback!

[+hogrod]

Picked up a Legend CX. Took the same walk this morning. No wandering . . .

Also, my son has an old Legend, no wandering. Friend of mine has the Rhino, no wandering.

 

Thanks for all the feedback!

 

LOL this makes me laugh so much.... ALL GPS have wandering tracklogs in poor signal areas(magellan, Lowrance, and garmin it doesn't matter). The reason you notice it more on the 60cx is the unit updates it's position much more frequently than most receivers.

looking at the picture in your first post looks exactly like when I leave my 60cx on sitting on my desk......BUT if I look at the average coordinates I am getting It's usually within 10-20 feet of the actual coordinates. it's only a few minutes every hour it is off by more than that.

 

The easiest fix for the wandering tracklog is to turn down the frequency of how often it makes tracks. my main complaint with both my legendC, vistaCX, and 60cx is they start logging a tracklog to soon after getting signal lock, which can cause 500ft or more errors in the tracklog.

 

The best example of how much quicker the 60cx receiver is to compare it to my legendC and vista CX. indoors I can get satellite lock on all three, though only the 60cx wanders allot. If all three are displaying incorrect position the 60cx will usually be correct within a minute, where as the slower receivers of the etrex models may take 5minutes to figure out they are wrong.

I'll deal with the wandering(usually only happens indoors), it's just a side effect of the faster processing receiver.

[+Petermgr]

LOL this makes me laugh so much....

 

Glad to make your day.

[strumble]

Hi everyone,

 

I picked up a Garmin 60CX yesterday and have been testing it out. Last night we went to find a geocache, no problems. However, I have noticed that the tracking wanders. I tested it this morning walking from my front door, around the block, and and back. When I imported the data into my Mapsource and into Google Earth I noticed a lot of tracks that I never made. Can't figure it out. The walk was consistent and the GPS had clear view of the sky.

 

 

WAAS enabled. MAP Datum, WGD 84. And btw, as I sit here at my desk, the tracking keeps moving on the GPS screen . . .

 

Any thoughts?

 

Thanks

 

Peter

 

I think:-

All this indicates is that you switched on the unit [in your home] prior to to your walk!

Post your actual 'track properties' to show when you were 'active' i.e. walking rather than just in your home! The details circled in red are not really the track but the record of the unit in the home!

 

Your later posting showing the Legend shows a less acurate track, unless you always walk in the middle of the road and only proves that you did not switch the unit on so early, before stepping out to complete the walk!!

 

To me the 60 gives a more accurate track record of your progress around your neighbourhood!

[Grasscatcher]

In the 60,76 x series ,the reason they call it a "high sensitivity" chip is because it is highly sensitive......DUH ! That means that it receives and records more signals more often.....both good and not so good. Multipath and reflected signals when you are moving slow or standing still cause what you are seeing.

 

If you don't like it, then use a dummied down version GPSr without the high sensitivity chip like the E-trex series.(note in above posts that the units without the "problem" are non "hs" units) Just wait and see, when the H series E-trex units get on the market, with the "hs" chip, they will have a similar "problem". What you are actually seeing is the increased sensitivity that allows better / greater reception in marginal areas.

 

Units like some of the Magellans that constantly "average" won't show as much wandering.

 

If you were to see the complete data from even one of the $5000-$10,000 surveyor grade GPSrs, it would be even worse, but thru software manipulation and filtering, positions are averaged and multipath signals are rejected so that final data is more accurate (and smoother). You can easily do some of the same "cleaning up" of the track in Mapsource.

 

What you are seeing is not a "GPSr unit" problem, it is more of an "operator not understanding the GPSr"

problem. This is not intended to sound critical. Not understanding what you are seeing leads to questions and that leads to answers and opinions, which lead to more experimentation, which lead to more understanding (or more questions)...etc.

Edited June 3, 2007 by Grasscatcher

[+Petermgr]

 

What you are seeing is not a "GPSr unit" problem, it is more of an "operator not understanding the GPSr"

problem. . . .

 

 

Ok, I agree that not understanding may be my problem. The 60CX is a great unit and reviews reflect that.

 

I am new to GPS and my attempt with the post ("Can't figure it out . . . Any thoughts?) was to understand why I was seeing such tracking on the 60CX. Prior to getting the 60CX I had used my son's Legend (old blue model) and did not see such ghost tracking. I also tested the Legend CX and did not see such ghost tracking. Given the detailed explanations in the responses has now educated me to the "why". So, without making comments against the 60CX I am simply stating that the Legend CX is the better unit for "me". I guess there are times where a person can buy too much technology and in doing so can cause themselves confusion . . . .

 

Thanks again,

 

Peter

[Grasscatcher]

Neither the old blue legend or the new Legend CX have the "high sensitivity" chip, therefore no wandering or ghost tracking. ( the x only refers to the memory card in the E-trex series) You will come to appreciate the better reception of the 60Cx vs the Legend, resulting in fewer dropped signals under cover , but also resulting in some strange trackpoints.

Just know that those bad ones are generally obvious (as you noticed) and can be edited away in Mapsource. Overall the track is more accurate.

Other than that, just enjoy your new GPSr and keep asking questions.

[+EraSeek]

The sirf chip picks up every signal, uses every signal, good or bad, with the philosophy that it will use everything to try and find your position and that that is better than no position at all. I have heard unit comparisons state that this unit is like a 4 wheel drive model (keep up upright on bad roads) where other units are like sports cars (precision on good roads, but lose it on the dirt).

 

I went on a hike up a forested mountain yesterday. I had a 60cx, my friend had a 60c. At the top of the 4 miles hike I had 7 miles logged and a screwy track, but never lost signal. He often lost signal and I suppose had no where near 7 miles.

 

The 60 cx has some great features, and some bad ones. I for one am setting my track to less frequent updates to see if that helps. Think I'll use my Garmin 12 every now and then.

[+Searching_ut]

A lot of people in this forum are saying that it is normal...i don't agree...may be normal for a 60cx but not for many other models....my 60cx does the same thing, but my legend c never did, and my current legend cx doesn't do it either....the tracking on those two is much more reliable than on my 60cx..when i use the gps on walk in fishing trips, i can follow the track out with the 2 legends, but with the 60cx, i cannot trust it's track...mine is for sale.

 

I realize that yes, consumer grade GPS's will have a certain degree of wandering, but that's not what i'm talking about. I'm talking about the reliability of the track put down by the gps. The track with my 60cx is NOT reliable. I don't trust it. I have full confidence in my legends. I've walked hundreds of miles with gps's, and i don't trust the track on the 60.

 

It's normal for the etrex series as much if not more so than the sirf chip models. I've logged thousands of track miles hiking and mountain biking with GPS's and they all tend to have track offsets, wandering and other errors, often with the error being several hundreds of feet. It doesn't matter whether I use my Pocket PC based units, one of my several different etrex's, one of my sportraks, or any of my Forerunners. If you use the unit with road maps and lock to road turned on, it looks good, but thats because the track record is based on the computed position with the lock to road function. My magellans don't wander when stationary because of the auto averaging, but they still drift way off sometimes when recording tracks, all depending on the terrain.

 

If you're looking to record highly accurate trail data with any consumer level unit, you're going to have to cover the same trail several times, manually take care of obvious errors, then average out the trail data with software such as topofusion.

 

No, as I said before, that is NOT the case with my other GPS's in comparison to the 60cx. As a matter of fact, just last evening (after my previous post) a friend and I rode 9 km on our atv's to go fishing. On the way out, his track was dead on, mine was 50 to 100 meters off MOST OF THE WAY OUT!! So to say that it is as much or more so in the etrex series is very innacurate. My friend's gps is a Legend C.

 

It's quite possible that in using the 60cx on your atv, you had it in a position that was far from optimal for the antenna type. I've done a fair bit of side by side testing of both the 60 and 60x series in combination with other GPS units and must say again I haven't found the track discrepancy to be significantly worse than most other units. For the sort of testing I've done, check out my webpage which you'll find in my profile. Unfortunately, the data is about 4 years old now, and there are a couple bad links which I can't fix being as how I quit using earthink as an ISP a little over 3 years ago. I can't update the page, and don't even know why it's still there.

 

As for the reception/track capability of the etrex color units, I've been quite a fan of them for years. They do tend to wander though, and depending on conditions, not get any reception at all. Most of my tracks are from peak bagging and hiking, but I do use the GPS for caching on occasion. A couple weeks agon while on the 6 mile round trip hike to GCK36A, my vista C only got reception about half of the time, and wandered, drifted and had other errors a great deal of that time. For the last .13 miles to the cache, I had no reception at all, and had to go by the clue. Basically just worked down the base of a cliff till I found it. (Steep canyon with 600 to 1000 foot sandstone walls). On this trip, I was mostly keyed on photography and didn't bring a second GPS unit to do side by side comparisons, but would suspect that virtually any unit would have shown a track that wandered all over the place. Again, all consumer grade GPS units I've used have quirks, you just have to get used to them and work around them. None of the ones I used to date are completely reliable when it comes to recording tracks, with error rates varying from as little as 10 percent or so to well over 50 percent depending on terrain.

[+mo_town_man]

 

I think:-

All this indicates is that you switched on the unit [in your home] prior to to your walk!

Post your actual 'track properties' to show when you were 'active' i.e. walking rather than just in your home! The details circled in red are not really the track but the record of the unit in the home!

 

Your later posting showing the Legend shows a less acurate track, unless you always walk in the middle of the road and only proves that you did not switch the unit on so early, before stepping out to complete the walk!!

 

To me the 60 gives a more accurate track record of your progress around your neighbourhood!

 

Could be since the 60 is able to pick up in his house, he got a lock in his house then went for his walk...

 

Where the other GPS can't get a lock in his house. So he went outside, turned it on, prob. drank a beer or 2, then headed out on his walk...

 

So maybe the ability of the 60 to lock in indoors in a way cause this result...

 

Just guessing here...

 

--danny

[+Petermgr]

I think:-

 

- All this indicates is that you switched on the unit [in your home] prior to to your walk! < If you say so.

 

- The details circled in red are not really the track but the record of the unit in the home! < If you say so.

 

- Your later posting showing the Legend shows a less acurate track, < If you say so.

 

- unless you always walk in the middle of the road < I did at times . . .

 

- and only proves that you did not switch the unit on so early, before stepping out to complete the walk!! < If you say so . . . and what's with the "!!"?

 

To me the 60 gives a more accurate track record of your progress around your neighbourhood! . . . If you say so.

 

Why are you coming across so aggressive?

 

Peter

[+Petermgr]

 

. . . . So he went outside, turned it on, prob. drank a beer or 2, then headed out on his walk...

 

Just guessing here...

 

--danny

 

I'd say . . .

[strumble]

I thought you were looking for the reason for the 'extra' tracking in and around your home, which we get in Wales with the eMap, iQue, GPSMap 60CS and 60CSX.

 

The 60CSX is so powerful at picking up a signal in my office [nowhere near a window and 12feet under a roof] that it regularly gives me a three to four WAAS satelite pickup, but it wanders as yours does until I leave the office, then it is as good any.

 

Why are you coming across so aggressive?

 

I thought I was being helpful not aggressive

[+mo_town_man]

I thought you were looking for the reason for the 'extra' tracking in and around your home, which we get in Wales with the eMap, iQue, GPSMap 60CS and 60CSX.

 

The 60CSX is so powerful at picking up a signal in my office [nowhere near a window and 12feet under a roof] that it regularly gives me a three to four WAAS satelite pickup, but it wanders as yours does until I leave the office, then it is as good any.

 

Why are you coming across so aggressive?

 

I thought I was being helpful not aggressive

 

U wanted to know the reason for the wondering tracks, and people with experience tried to explain

what may have caused them, thus possible answering your question.

 

I can see why you might be a little miffed, if you was wrong about the reason and they are right. Specially,

if u really did turn it on inside before the walk....

 

If u still got the 60CSX, why don't u simply wait till outside and turn it on at the same place you did the other unit then go for your walk. Then turn off before getting inside...

 

Would seem simple enuff to prove one way or the other...

 

--danny

[GreatCanadian]

Mounted on handlebar while riding wide open terrain with no hills or trees around for miles. My buddy had his legend c mounted the same way.

 

My point in this thread is NOT the wandering but the discrepancy in 2 tracks laid down in the same place. Mine show (for the most part) 2 parallell tracks anywhere from 50 to 100 meters apart. I went in on a trail, and came out on the same trail. The 2 tracks laid down by the GPS are not even close. (They are at points, but generally 50 meters or more apart). Both tracks laid down by the Legend c are extremely close. Wandering is not the problem in this situation. My 60cx lays down the WRONG TRACK. And if you believe that the 60 cx is more accurate than the legend c, I'll take the legend c, as it's track is obviously more reliable in this case. If the 60cx is more accurate, how am I to know which track is the accurate one of the 2 laid down. And if you read other forum threads, you will see that this is a fairly common problem with the 60cx. I it is caused receiving bounced signals or signals from the horizon, then someone needs to find a method to filter these signals in the 60cx. While fishing yesterday, I noticed a cache on my gps. So I paddled the canoe to shore to take a quick look. The cache was supposedly nearby. I got to ground zero and the gps told me I had to go 56 meters east to get to the cache. That would have put me about 20 to 30 meters out in the pond. I didn't waste any more time looking, and went back to fishing. That problem is NOT wandering. Now dont' get me wrong, the gps has put me dead on coordinates at times. But not often enough for me to trust it. It isn't my first gps, I've had dozens, and use them extensively. This one has not earned my trust yet.

 

 

It's quite possible that in using the 60cx on your atv, you had it in a position that was far from optimal for the antenna type. I've done a fair bit of side by side testing of both the 60 and 60x series in combination with other GPS units and must say again I haven't found the track discrepancy to be significantly worse than most other units. For the sort of testing I've done, check out my webpage which you'll find in my profile. Unfortunately, the data is about 4 years old now, and there are a couple bad links which I can't fix being as how I quit using earthink as an ISP a little over 3 years ago. I can't update the page, and don't even know why it's still there.

 

[RenHoek]

Hi, Peter-

One feature of the 60CSx you might not have been aware of is the ability to customize the track recordings. You can configure the recording method to be either based on Distance, Time, or Auto. For Auto, there are 5 settings - Most Often, More Often, Normal, Less Often, and Least Often. The distance/time settings are self-explanatory. You could probably find a better setting for what you're wanting to see.

 

For me, the main reason I waited so long to upgrade from my old GPS12 was the higher sensitivity. You'll definitely notice the difference between the Legend and the 60CSx once you get off the open streets and into the woods.

 

-RenHoek

[segler999]

I have compared the tracks of my 60Cx and Legend (old blue) several times. These are for hikes in open ground. The Legend can have problems under dense tree cover, so if I want to make a comparison, I have to optimize the acquisition conditions for both units.

 

The best way to set this up is to set both units for time at 1 second, not any of the auto settings. That way you don't have to rely on a mysterious algorithm to decide when to take the next point. Just take a new point every second regardless.

 

Make sure NOT to save the tracks. Instead, use ONLY the active tracklog for one session, then download it into the computer. That way, you get ALL the points, not just the 500 that are kept when you do a save.

 

When I compare the resultant tracks they are very close.

[+apersson850]

As I recently got a 60 CSx as well, this year I used that, the old eTrex Vista and a Forerunner 301 to measure the length of a hike my orienteering club organizes every year. It's a new trail each year, so I measure it again every year.

 

The terrain where we walk is mostly Southern Swedish forestry, with quite a lot of canopy occasionally. Before, when having first only the eTrex Vista, then the Vista and the Forerunner 301, there have almost always been parts of the track missing, various oddities when they almost loose reception and so on. This has required editing of the track logs in Mapsource, before I can present the result on a printed map, with elevation profile, to the participating hikers.

 

This year, the situation was the same as before with the two older units. The Vista added 600 meters to the track when I happened to turn it upside down for a while, while poking a stone out of my shoe. The track log showed it rushing around the area in a few seconds, when that happened. At the end of the 20 km hike, the Vista was off by 1.7 km, compared to the 60 CSx. The Forerunner was much closer to the 60 CSx, as the Forerunner was always situated at a favorable position on my wrist. Additional measurments on the maps available, including City Navigator Europe, but also other orienteering maps, all indicated that the 60 CSx was very close to the truth. So close, that I for the first time in the history of organizing this event could use the track log without editing it first, when creating the printed map of the hike.

 

I agree fully in that the 60 CSx is a much better GPS than units like the Legend Cx and similar, when the going gets tough. That the simpler units don't wander around that much is simply because they don't have a clue about where you are. I can also see that under the same conditions, when walking or running along roads, the track log from the Vista or the Forerunner make all sorts of detours away from the road. The track recorded by the 60 CSx very often make the road disappear on the map view in Mapsource, as it's obscured under the track. Note that this is at speeds when "lock on road" doesn't engage.

[+EraSeek]

Apersson850, which setting do you have it on; Most Often, More Often, Normal, Less Often, and Least Often?

[+apersson850]

Automatic and normal in all units where you can influence it.

[GreatCanadian]

 

I agree fully in that the 60 CSx is a much better GPS than units like the Legend Cx and similar, when the going gets tough. That the simpler units don't wander around that much is simply because they don't have a clue about where you are. I can also see that under the same conditions, when walking or running along roads, the track log from the Vista or the Forerunner make all sorts of detours away from the road. The track recorded by the 60 CSx very often make the road disappear on the map view in Mapsource, as it's obscured under the track. Note that this is at speeds when "lock on road" doesn't engage.

 

There are a couple of statements among your post that I have issues with. First of all that the simpler units don't wander around simply because they don't have a clue where you are. Well, if that's the case, my Legend C didn't have a clue where I was in exactly the same manner both on the way in and out the same track. That means it is very accurate at not having a clue where it is. Maybe not precise, but accurate. That's good enough for me. As for the track obscuring the road on a map, I would venture to guess that that would be true as the maps are NOT known for their accuracy, and I would expect the track to be on it sometimes and off it sometimes with just about any gps. Happens with both my Legend and 60cx. It seems to me that the variance in the tracks laid down by my 60cx seem perfectly acceptable to you guys because the 60cx has the high-sensitivity chip. My point is I CAN'T RELY ON THE TRACK ON THE 60CX to lead me out the same way i went in. I CAN do that with my Legend. the Legend's tracks are MUCH closer together than that of the 60cx. Without any explanations of WHY, tell me which I should trust more if I NEED TO RELY ON MY GPS TO LEAD ME OUT. I park in my driveway and my 60cx tells me my driveway is 60 meters away. Did I mark it wrong? Well if so, that's where it told me it was when I marked it. So which is right. My Legend tells me sometimes it's 8 or 10 meters away, but never 60. This is a constant problem, not a onetime thing. And I would believe it as a defective unit except for the fact that I've seen the same problem posted quite a few times on this forum. Can my 60cx lock on in my basemsent? You bet it can. But I don't often get lost in my basement.

Edited June 4, 2007 by GreatCanadian

[+whitecrow]

60 meters? My 60cx usually shows around 20 feet at most at home.

Edited June 5, 2007 by whitecrow

[MajBach]

 

LOL this makes me laugh so much.... ALL GPS have wandering tracklogs in poor signal areas(magellan, Lowrance, and garmin it doesn't matter). The reason you notice it more on the 60cx is the unit updates it's position much more frequently than most receivers.

looking at the picture in your first post looks exactly like when I leave my 60cx on sitting on my desk......BUT if I look at the average coordinates I am getting It's usually within 10-20 feet of the actual coordinates. it's only a few minutes every hour it is off by more than that.

 

The easiest fix for the wandering tracklog is to turn down the frequency of how often it makes tracks.

 

I fail to see how this is at all relevant. An more frequently updated track only serves to emphasize the error. My old Lowrance could update just as fast. The point is, it didn't wander. Actually, it did, but it had a funtion to eliminate this because the designers anticipated low signal and reflection. Imagine if your FM radio picked up every sky wave signal on the frequency it was set to and you had to lisen to several stations at once. Hmm, I think they built something into radios a long time ago that eliminated weak/errorneous signals. Garmin should have done this too.

 

I believe for the total $$$ I have spent on the unit, I should be able to leave it stationary in the open and NOT see the odometer slowly climb when the unit never moved.

Don't get me wrong, I don't even touch the Lowrance now that I have the 76 - the two don't compare. But this is a predictable, fixable result that should have been addressed by Garmin because in this partiucular instance, the outdated competitor's technology is superior (or at least more useful) than Garmin's.

Edited June 5, 2007 by MajBach

[MajBach]

 

- All this indicates is that you switched on the unit [in your home] prior to to your walk! < If you say so.

 

- The details circled in red are not really the track but the record of the unit in the home! < If you say so.

 

- Your later posting showing the Legend shows a less acurate track, < If you say so.

 

- unless you always walk in the middle of the road < I did at times . . .

 

- and only proves that you did not switch the unit on so early, before stepping out to complete the walk!! < If you say so . . . and what's with the "!!"?

 

To me the 60 gives a more accurate track record of your progress around your neighbourhood! . . . If you say so.

 

Why are you coming across so aggressive?

 

Peter

 

Becasue you are being objective where many others are being subjective. The latter often leaves the ego a little vulnerable.

[+Petermgr]

BTW, nice pic. I have one from the same spot from the last time I was out there.

 

Thanks Majbach . . . We have lived here over 25 years and only now discovered this view. We expect to see even more interesting views now that we are into this GPS and geocache experience . . .

 

Peter

[+EraSeek]

The whole key is the sirf chip. The legend and other units toss out questionable signals and uses the better signals only. The sirf chip uses good and bad and trys to get accuracy by doing a gizillion calculations. There are things I don't trust about the 60cx and things I love. My own feeling is that you give up some accuracy for always haveing signal and being somewhat close in bad areas. The best way to keep the 60cx more stable is by using WAAS when it will take. On my experiments on benchmarks the 60cx will stay real steady on the mark when WAAS is in place.

[+Petermgr]

Just to clarify a few things . . .

 

My post was a request for understanding why I was seeing what I saw on the 60Cx. It was showing me something I had not seen before on an old Etrex Legend or an Extrex Legend Cx. A number of answers to my post educated me as to the "why" and gave me a better idea of how the 60Cx works with the SiRF chip.

 

However, without intention, some posts may have indicated that the 60Cx was not a good GPS unit. That certainly was not my intention with any of my responses. When I indicated that I was going to settle on the Legend Cx and return the 60Cx, it was simply a choice of which product would be better suited for me. And yes, that choice was partially based on some of the feedback I read.

 

Having said that I do want to understand, if for no other reason but to be educated, how does a highly sensitive SiRF chip filter signals? Can it determine if some are false as opposed to signals that are true direct signals from a satellite? And with the collection of signals for determining a GPS location, can a SiRF type of chip get confused by a signals that bounce of aluminum siding on my home? And if I had a GPS unit with a SiRF chip while out on a hike, can I expect ghost readings if a radio tower is nearby? Might be stupid questions, but I am curious.

 

Thanks again . . .

 

Peter

[+hogrod]

 

LOL this makes me laugh so much.... ALL GPS have wandering tracklogs in poor signal areas(magellan, Lowrance, and garmin it doesn't matter). The reason you notice it more on the 60cx is the unit updates it's position much more frequently than most receivers.

looking at the picture in your first post looks exactly like when I leave my 60cx on sitting on my desk......BUT if I look at the average coordinates I am getting It's usually within 10-20 feet of the actual coordinates. it's only a few minutes every hour it is off by more than that.

 

The easiest fix for the wandering tracklog is to turn down the frequency of how often it makes tracks.

 

I fail to see how this is at all relevant. An more frequently updated track only serves to emphasize the error. My old Lowrance could update just as fast. The point is, it didn't wander. Actually, it did, but it had a funtion to eliminate this because the designers anticipated low signal and reflection. Imagine if your FM radio picked up every sky wave signal on the frequency it was set to and you had to lisen to several stations at once. Hmm, I think they built something into radios a long time ago that eliminated weak/errorneous signals. Garmin should have done this too.

 

I believe for the total $$$ I have spent on the unit, I should be able to leave it stationary in the open and NOT see the odometer slowly climb when the unit never moved.

Don't get me wrong, I don't even touch the Lowrance now that I have the 76 - the two don't compare. But this is a predictable, fixable result that should have been addressed by Garmin because in this partiucular instance, the outdated competitor's technology is superior (or at least more useful) than Garmin's.

 

yes lowrance does have a track smoothing feature that helps a ton with track errors, I was trying to make the point that ALL GPS have tracklog errors & none are perfect. It would be great if garmin had a track smoothing feature like lowrance, which seemed to me makes the unit average its position in the background somewhat so you don't get 30ft away one minute & 2ft the next. My lowrance ifinder h20 was MUCH more stable near ground zero than my 60cx, and usually closer

 

Just like ALL gps have tracklog errors, ALL will pickup some distance moved when stationary in the open, though the 60cx does seem to move a bit more than all the others. over an hour time my 60cx may say 80ft on the odometer, my legendC, and vistaCX about 30ft. I no longer own a lowrance or magellan but I know they also would pickup some odometer movement even when stationary.

[+EraSeek]

Having said that I do want to understand, if for no other reason but to be educated, how does a highly sensitive SiRF chip filter signals? Can it determine if some are false as opposed to signals that are true direct signals from a satellite? And with the collection of signals for determining a GPS location, can a SiRF type of chip get confused by a signals that bounce of aluminum siding on my home? And if I had a GPS unit with a SiRF chip while out on a hike, can I expect ghost readings if a radio tower is nearby? Might be stupid questions, but I am curious.

 

Thanks again . . .

 

Peter

Not stupid questions. I can't answer them for sure, but I did read about this once. Just wish I could recall. If I recall correctly, yes the sirf chip has some abilty to detect and correct or adjust for multipathing (bounced signals). Regular units also have some very minor allowence built into the software for this, but the sirf chip is more actively detecting mutipathing. Not gospel, just frail recall on my part.

[+EraSeek]

here: http://www.pocketgpsworld.com/bt338.php

 

"The new chipset also features a different approach to the usage of the actual satellite signal. Where standard receivers require a signal strength of at least 28 dB to even consider a satellite for correlation the SiRFstarIII chipset will basically use any signal it can get, down to 13 dB. Thanks to its 20 channel receiver it will also be able to use signals that are bouncing off buildings (especially in urban canyons, but also indoors) and include them into the correlation.

 

 

This is similar to the way that XTrac works on the SiRF II chips, but without the negative side effects. Where the SiRF II/XTrac chips tended to “overshoot” position and generally took more time to calculate position the new SiRF III is staying close to the course you are driving, no matter how hard you accelerate or brake or turn.

 

 

Due to the fact that it can use such low signal levels the new chipset is also performing better under foliage, in urban canyons, and indoors. It basically scratches every single bit of signal off the wall and uses it for the correlation.

 

 

This approach of course also comes at a price. If you use such low signal levels, you will also get some pretty bad signals that will make your position jump around quite a bit when you are stationary or moving slowly. SiRF's answer against that is called “Static Navigation” and it is a feature of the chipset that freezes your position when you are moving slower than 4 km/h . Position changes will only be registered when the difference exceeds 50 meters. As a result when you walk slowly your position seems to be frozen and it updates only every once in a while.

 

 

Sounds familiar? Indeed, this feature was also present in the XTrac chipset, and it caused some grief with the pedestrians and Geocachers. Fortunately this feature can be switched off with a tool called SiRFDemo. Guillaume over at GpsPasSion has written a brief tutorial on how to use SiRFDemo - http://www.gpspassion.com/forumsen/topic.asp?TOPIC_ID=25575 (you need a Bluetooth enabled PC for that) "

Edited June 5, 2007 by EraSeek

[+Petermgr]

here: http://www.pocketgpsworld.com/bt338.php

 

 

Thanks for the link and information. Very interesting read . Does help to understand how it works . . .

 

Peter

[+apersson850]

My experience so far says that my 60 CSx will indeed wander a lot, if I turn it on in my bedroom, for example. The Vista will not do that there, as it has no clue where it is.

 

It's likely to be so, that when you go from "impossible" to "just possible" for the Vista, it's not that easy for the 60 CSx either. One reason a Vista, in such a case, may give a better track could be this scenario:

 

Assume you are standing in a clearance. Both GPS devices have a reasonable fix, and show about the same position. Now you start moving through a narrow canyon, where signals are very weak. Say it will take you 25 seconds to pass it.

During the passage of the canyon, the Vista can't make any sense of the weak signals, so it will report the same as it did when you entered the canyon. Once you come out at the other end, it will correct the guesswork it has performed, based on the same speed and direction as you had when you entered the canyon, and put you back where you are. When you inspect the track log, it seems perfect. Some points before the canyon, a line through it and some points after. Perfect.

 

The 60 CSx, on the other hand, will be able to sort something out of the weak signals at the bottom of the canyon as well. But due to excessive multipath, it will be fooled into believing it's sometimes outside the canyon, when it really isn't. Once you get out, it will have good signals and put you back in the correct position again. When you look at the track, and compare it to the one laid out by the Vista, the 60 CSx's track looks horrible.

 

So, just like it was commented above, just because the Vista doesn't have a clue about where you are, it will fake a nice looking track for you. This only works if you don't stay too long in the canyon, of course, or it will tell you that it lost contact with the satellites. At that time, the 60 CSx will still deliver a position, even if it's not perfect.

 

GreatCanadian, you may have as many issues with my statements as you like, but I still claim it's due to lack of understanding of the rather complex math that goes on inside your navigator.

 

Navteq claims their detailed maps to be accurate to within 10 meters, by the way.

[+Fuchsiamagic]

I have a 60 and a 60CSx and was trying to find a cache in a small town square this morning. The square had 2 and 3 story buildings surrounding it and was about 100 yards across.

 

When I arrived and turned on both units, the 60CSx aquired within 30 seconds and although I was stationary in the middle of the square, the tracks it displayed where all over the place as signals bounced off the buildings. The map was actually moving on the display as though I was walking along! It did eventually settle down after a few minutes and led me to within a few feet of the cache site.

 

Meanwhile, the 60 was still trying to aquire a signal. I know which one I prefer...

Edited June 5, 2007 by Fuchsiamagic

[+CrkrJim]

I'm a construction superintendent working on a 30acre site. My trailer is at one end against the woods. When I got the 60csx for my birthday a month or so ago, I decided to play with it at work. I used it as a pedometer to see how much I walked at work (3+mi a day). I quickly learned to turn off tracking as soon as I got back to the trailer as the wandering track log would soon obscure my trailer area when loaded to the computer. I would also take my distance reading as soon as I got in the trailer as the milage kept piling up while it sat on my desk. First gps I've had that would get signals inside a metal building.

 

I decided to explore the woods behind the trailer one day as a large hawk was hanging in the area. I turned on the tracking and went into the woods. Fairly dense foliage but good signal all the way. Just for practice, I backtracked back out and was impressed with the accuracy of the track. This was easy to see since if it had taken me off track, I'd be pushing through dense undergrowth.

 

To me, the signal aquistion in the woods is worth the wandering of track and odometer when standing still. For geocaching, I use the compass and circle around the area (usually just a few feet farther out that indicated accuracy) and get a consensus of the "ground zero" to start the hunt.

 

I don't worry about the maps too much around here. Since this is a high growth area, there are many roads not on the maps. I don't navigate by road to get to the cache area . We'll be doing some traveling to other areas this year. The road navigation will come in handier then.

 

Good luck,

 

Jim